摘要:
利用2010和2012年黄海海域不同季节的航次观测数据与HYCOM模式再分析数据进行了比对,检验了HYCOM模式的水体温度数据在黄海海域的适用性。据此分析了黄海海域的温度锋面和混合锋面的时空变化。结果显示,温度锋通常在秋季开始出现,在冬季最为发育,在春季逐渐消失;黄海混合锋面与季风活动密切相关,主要在秋季开始出现,在冬季发育。悬浮沉积物基本上集中在温度锋的向岸一侧,难以跨越锋面输运。山东半岛成山头海域的温度锋在形态及空间位置上与泥质沉积区相对应,沉积中心(厚度40 m)主要分布在温度锋的西侧,而在其东侧泥质沉积厚度快速减小。研究结果发现,秋冬季节混合锋与温度锋的空间位置并不一致,混合锋位于温度锋的西侧,强烈混合使得沉积物不易沉降,对应泥质沉积厚度小;而在混合锋东侧,悬浮沉积物浓度高且水体层化显著,沉积物易于沉降堆积,与泥质沉积中心对应。混合锋与温度锋的空间分布差异与共同作用可能是该区域泥质沉积体"Ω"形态发育的动力学机制。
Abstract:
In-situ water temperature data collected during different seasons in 2010 and 2012 was compared with HYCOM reanalysis data. The results illustrated that temperature data derived from HYCOM is applicable in the Yellow Sea. Based on the HYCOM datasets, temporal and spatial variability of the thermal front and mixing front in the Yellow Sea was analyzed in detail. The results showed that the thermal front appeared in fall, became strongest in winter and disappeared gradually in spring. Seasonal variability of mixing front in the Yellow Sea was related to monsoon. Mixing front appeared in the fall and well developed in the winter. Suspended sediment was concentrated in onshore side of the thermal front that constrained the offshore transport. The thermal front in Chengshantou coastal area corresponded to mud deposit in shape and location, as the depo-center (40 m thick) was located at the onshore side of the thermal front while on the offshore side the mud thickness decreased sharply. The results indicated difference between locations of the thermal front and mixing front, as the mixing front was located at the west of the thermal front where strong mixing was unfavorable for sediment accumulation. At the east side of mixing front, suspended sediment concentration was high with low turbulence, which favored rapid sediment accumulation corresponding to the mud depo-center. The spatial differences and interaction between the thermal front and mixing front might be the dynamic mechanism dominating the formation of omega ("Ω") -shaped mud deposits.
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